1. Field of the Invention
The present invention belongs to the technical fields of a network system, an information processor, and a recording medium storing information programs. More specifically, the invention belongs to the technical fields of a distributed network system in which a distributor delivers information to information processors that connects each other in a hierarchical fashion for relaying the information from end to end stepwisely.
2. Description of Related Art
In recent years, as the speed of the Internet line for home use increases, a network system is being widespread. In the network system, a network is constructed by connecting a plurality of personal computers or the like in houses or the like in a hierarchical tree structure using, at its apex, one distribution server as a distributor. Via the network, so-called content such as music and movies as distribution information is distributed from the distribution server.
The network will be called “topology” from the viewpoint of the logical network connection aspect. In the topology of such a network, each of the personal computers constructing the network is generally called a “node”. Further, for example, Japanese Patent Application Laid-Open (JP-A) No. 2006-287351 (FIGS. 1 and 2) discloses a conventional technique of the network system.
In the technique disclosed in JP-A No. 2006-287351, in the case where a new node newly participates in a network system having a hierarchical tree structure, first, the new node sends an inquiry to newly participate in the network system to a topology controller. A connection request is sent from the new node to a connection destination node (any of nodes already participating in the network system) which information is included in a reply from topology controller to the inquiry. The new node is newly connected to the immediately downstream side of the connection destination node. In such a manner, the new node newly joins the network system.
In this case, the topology controller controls the topologies (connection destinations) of all of nodes belonging to the network system.